It's not much yet but it will be. This is more of a side project. what will make this tank different than most one I have seen will be the drive system. it uses double differential steering instead of simply having one motor for each track. this allows it to be controlled like a regular wheeled vehicle. There is a drive shaft input and a steering input. the gears on the top slow down one side of the track depending on which direction the shaft is turned. This also makes neutral steering very easy. simply turn the "steering wheel hard in one direction and hold it and it will neutral steer. Almost all modern tracked military vehicles use this kid of system, except there is usually a third differential between the steering gears that turns of the drive shaft. then to steer this system there is a brake on each side of the steering (3rd) differential to stop one axle to make a turn. When I was in the marine corps I was a crewman (driver) on an Abrams tank, and learned quite a bit about tanks and their mechanics, so I figure it is time to build one.
here is a link to an animation of this http://www.gizmology.net/tracked.htm. scroll down to the "double differential steering section"
Very very clever. Enough said. These are the solutions that Lego should use in coming models. I would like to see more models based on real vehicles and a revival of the Kässbohrer snowmobile could lead the way!